Article of manufacture



ARTI CLE/ OF/MANUFACTURE Filed Dec. 31. 1937 "go X David Juuvdn BY y `K A TTORNEY x Parenteel May 21, 1940" Annan or MANUACTURE Davia J; Sullivan, Fahnen, oonnl, signor to u E. I. du Pont de Nemours & Company, WilningtomDel., a, corporation of Delaware Application December 31, 1937, Serial No. 182,725

7 Claims.

This invention relates to artificial leather, and more particularly,jto an improvedleather substitute comprising a flexible backing to which* is applied an improved coating composition of rubber or rubber-like materials.

Heretofore articial leathers have been characterized by a lack of leathery feel, despite the numerous expedients tha make them simulate genuine leath'er. These artificial leathers heretofore known have all fallen short, to a greater or less-degree, of an entirely satisfactory substitute for leather due to a lack of some essential quality of leather. Either they Adid not look like leather or they were stiii.' and board'y,- or rubbery, or were lacking l in draping properties, et cetera.

It was known that rubber coating compounds useful for 'making leathersubstitutes could not be embossed with suflicient sharpness and permanency to survive a vulcanizing treatment, unless the coating material contained less than about 50% of rubber and a considerable pertvhave been employed to.

centage of earthy fillers such as clay, magnesiumcarbonate, and whiting Sometimes fibrous materials were included with more or less earthy filler. These constituents were present in additionv to the necessary vulcanizing ingredients, such as zinc oxide together with sulphur, and other desired ingredients, such as coloring, softening, activating and accelerating agents.

However,'the leather substitutes made with all such coating compositions failed to approach closely the appearance or character of leather in some important noticeable respect. For example, the substitutes which contained earthy fillers were noticeablyunlike leather in that the specific gravity was too high. If they did not actually look like rubber compounds, the material was relatively too heavy for its thickness to 40 be a good substitute for leather, and its feel suggested ordinary oil cloth. Some of the leather substitutes were too boardy and some were too rubbery to resemble leather closely. Many'of the materials of the prior art showed edge cracking. Leather substitutes containing light non-earthy and non-fibrous fillers were-unlike leather in that they lacked the proper brous character of -leather and they had in addition some of the defects heretofore noted.

'I'his invention' had for` an object the preparation of an improved and a' more leather-like leather substitute. Qther objects were the provision of a rubber coated fabric leather substitute having a leather feel,lcontaining a high content ofl rubber, having good graining charac- Vteristics, which retains embossing marks toa satisfactory degree, which contains an appre ciable quantity of newsprint paper or wood fiber f in equivalent form, which resembles leather in point of vbulk (or specific gravity), which elimi- .s

nates the fboardyjfeel of ordinary leather substitutes, which eliminates the rubbery feeljof common substitutes for leather, which is 1mproved with respect to edge cracking, which has an improved leather-like feel, and which 10 looks like leather. A further object was to provide an artificial leather for garments, gloves, upholstery, and the like, which more closely imi'- tates genuine horse hide or cow hide in appearance and feel lthan the leather substitutes here- 1I tofore produced. Another object of the invention was the preparation of a rubber containing leather substitute composition whichwhen disposed 'on a suitable fabric would give a product resembling leather in such characteristics as 20 b ulk, feel, appearance and resistance to cracking upon exing. A general advance in the art and other objects which will appearv hereinafter are also contemplated. j

It has now been found thatv a leather-like leather substitute may be produced by applying Y to a flexible backing either with or wlthout an intermediate rubber cementl layer. a rubber composition containing an appreciable quantity of wood fiber in the form of newsprint paper evenly $0 dispersed throughout its mass and thereafter vulcanizing the product, coupled if desired, with further finishing treatment or treatments.

From the following description and specific examples in which are disclosed certain embodi- 35 ments `of the invention as well as details of what is believed to be the best mode for carrying out the invention, it will be apparent how the foregoing objects and related ends are accomplished. The quantities are weight throughout the application. The written description is amplied by the accompanying drawing in which:

' Figure 1 is a sectional view representing somewhat diagrammatically a preferred form of the 45 articial leather of the invention;

Figure 2 illustrates a. product similar to that of Figure 1 in which the top surface finishing coating has been omitted; and

Figure 3 illustrates a product similar to that 50 of Figure 1 in which an additional top surface nishing coating has been applied.

Similar characters refer to similar parts throughout the drawing and specication.

In one embodiment of the invention a web of given in parts by 40 sheeting indicated by the numeral l in Figure 1, weighing 5 ounces per square yard and having one side napped, was dyed black and coated on the unnapped side with a rubber cement composi- 5 tion a"t the rate of one to two ounces per square yard. This layer in position on the sheeting is designated by the numeral 2 in Figure 1. The composition Was spread on the web in the conventional manner. In commercial practice it is 1@ applied in one or more spread coats, depending upon the convenience of the operator. Any desired consistency may be obtained by the addi- `tion of gasoline. Obviously, more coats of a cement, which has been out very thin with a solvent 115 like gasoline, are necessary to secure a particular coating than are required with the thicker compositions.

A typical rubber cement composition is given in Example I.

30 Example I Per cent Plantation rubber 40 Palm oil 1 Zinc oxide 4 Baryte n 25 Whiting 28 Albasan (antioxidant) 0.5 Trimene base, (triethyl, trimethylene, triamine) (accelerator) 1.0 30 Sulphur 0.5

After the volatile solvent had been removed from the rubber cement layer 2, a coating 3 of a rubber coating composition was applied to the web over the rubber cement composition at approximately the rate of 14 ounces per square yard. Compositions of this character are preferably @i0 applied by a calender. The color of the final product (artificial leather) of this invention is largely determined by the color of the layer 3. A typical example of a rubber coating composition adapted to give black articial leather is as follows:

A typical specific example of a rubber coating composition for a brown artificial leather is as follows:

Example III 65 Per cent Plantation rubber 66.00

Iron oxide 4.00

Carbon black 1.3 Zinc oxide 4.00 70 Newsprint paper 21.55 Neozone D" .75 Trimene base 1.75 Sulphur .65

A typical example of a formula for a green artificial leather is as follows:

A thin coat 4 of quick drying shellac varnish 15 (comprising shellac dissolved in a mixture of water, denatured ethyl alcohol, ammonia, and soap) was applied to the rubberized surface of the web as it came from the calender. 'Ihls shellac varnish not only served as a surface fin- Y ishing coat but also removed the surface tack on the rubberized face of the web so that the same could be rolled up without sticking. In commercial scale manufacture a lint-free liner is run in the roll of web to protect the surface of the 25 unvulcanized rubber coating.

The coated web was thereafter passed through embossing rolls (embossing presses have also been used satisfactorily) to give the coating a characteristic leather grain. The assemblage was then $0 vulcanized in a hot air vulcanizing chamber for one and one-half hours at 250 F. (157 C.)

After the vulcanization step the coated surface of the product was treated with a 4% solution of bromine (by volume) in carbon tetrachloride to I5 indurate the shellac varnish layer. The product was thereafter and finally exposed to an atmosphere of ammonia to neutralize the indurated surface.

Wide .variations may be made in the rubber 40 coating composition as will be apparent from the above examples. The same is true of the exible backing and the rubber cement used to coat the same.

Instead of sheeting, any flexible backing can 4B be used, including woven or unwoven fabrics, felt and paper. Special mention may also be made of paper impregnated with rubber or other impregnating media. The back side as well as the front side of the backing may or may not be napped, and in any case may be given a coat of cement to mat the fibers to a certain extent to give the back side of the product a resemblance to the back side of split leather.

The invention is not limited to the use of nat- 5i; ural rubber. In another embodiment of the lnvention an unnapped web of sheeting weighing 6 ounces per square yard was coated on one side with a plurality of coats of neoprene cement so that one to two ounces of solids per square yard 60 remained deposited after the solvent had been volatlized by heating. The specific cement used had the following composition:

This composition was cut in xylene to the desired consistency before spreading. The preferred 1| 4. ing on the base, and such a modication is illusVJ trated in Figure 2. Alter the base has had the rubber or rubber-like coating composition applied, it may be vulcanized and, if desired, sub- .5 sequently indurated whether or not the shellac coating has been applied. Although it is pre- Zei-red to subject the product to a halogenizing treatment, this is not necessary as the product may be halogenizing treatment, or maybe nished with a shellac varnished top layer that has not been halogenized.

It will be understood that various decorative surface eiects may be produced on the coated web by combinations of embossing and souping, printing, stenciling, etc., as will occur to those skilled in the art. Likewise, varnishing or lacquering of the material over the first shellac varnish layer may beemployed to produce a product resembling glazed leather. Such a modification is illustrated in Figure 3, wherein (l represents the shellac layer and 0 a decorative varnish layer superimposed thereon.

g3 The indurating step is not limited to treatment oi the artiiicial leather with bromine dissolved in carbon tetrachloride, as any halogenizing treatment will produce more or less desirable results. For example, the rubber coated web,

lat) whether shellacked or not, may be treated with a solution of sulfur chloride or sulfur bromide in carbon tetrachloride, or other halogenizing agents.

The vulcanizing temperature and duration may 35 be widely varied, as will be fully understood by those skilled in the art of coating with rubber compositions.

Although it is preferred to apply the rubber coating composition by calendering, the compo- ',(0 sition may be thinned by a solvent such as gasoline and applied by spreading repeated coats of the same on the base.

The artiiicial leather produced in accordance with this invention very closely resembles genuine dressed leather in appearance, feel, pliability, wear, durability and draping qualities, and is superior to artliicial leather now on the market in these properties. A particular advantage o! this artificial leather, due to the newsprint `l0 wood fiber in the rubber coating composition, is

its resistance to abrasion and edge cracking at seams and folds, which resistance artificial leather heretofore known does not possess to anything like the same degree.

'55 The articial leather oi' the present invention is particularly adapted, due to the above mentioned properties, for making garments such as imitation leather coats, leggings, gloves, and belts, and also for making upholstery, quarter- W linings, shoes, purses. luggage, etc.

This application is a continuation-impart of my application Serial No. 53,242 filed December 6, 1935, which was a continuation-impart of my application Serial No. 513,610 tiled February 15,

As many apparently Widely different embodiments of this invention may be made without departing from the spirit and scope thereof, it

,7o is to be understood that I do not limit myself to the specic embodiments vthereof except as dened in the appended claims.

I claim:

l. Process which comprises coating the unu napped side of a sheeting weighing 5 ounces per finished with or without a shellac varl@ nish top layer (as above indicated) and with no asomar square yard dyed black and having one aide napped with a rubber cement of the formula Trimene base (triethyl, trimethylene, trios amine) (accelerator) 1.0 Sulphur 01.5 until 1 to 2 ounces of cement per square yard n have been deposited, applying over the said rub ber cement coating a layer o a rubber composition having the formula Percent Plantation crepe 66.635 53 Palm oil 1.000 Carbon black 3.500 Zinc oxide 4.000 Newsprint paper 21.69 INeozone D (phenyl beta naphthyla- .6

mine) (antioxidant) .75 'Irimene base (triethyl trimethylene triarnine) (accelerator) 1.75 Sulphur 1.675

coating the said rubber composition with a thin coat of quick drying shellac varnish, embossing the resultinglaminated sheet material, vulcanizing the said embossed material, indurating the said vulcanized material by applying a halogen u to the shellac layer and thereafter neutralizing the indurated surface.

2. A leather substitute very closely resembling genuine dressed leather in appearance, feel, pliability, wear, durability and draping qualities, which is obtained or obtainable by coating the "u vunnapped side of a sheeting weighing 5 ounces per square yard dyed black and having one side napped with a rubber cement of the formula Per cent .45

Plantation rubber 40 Palm oil 1 Zinc oxide 4 Barytes 25 mating--- 2e l Albasan (anti-oxidant) 0.4

Trimene base (triethyl, trimethylene, triamine) (accelerator) t1.0 Sulphur 0.5

coating the said rubber composition with a thin coat of quick drying shellac varnish, embossing the resulting laminated sheet material, vulcanizing the said embossed material, indurating the n said vulcanized material by applying a halogen to the shellac layer and thereafter neutralizing the indurated surface.

3. Anartificial leather comprising a backing of fabric napped on one side and having secured to the opposite side thereof a layer of vulcanized rubber cement and an indurated layer of vulcanized rubber composition containing at least 67% of rubber and the remainder Wood ber and nonearthy material, the ratio of wood ber A to rubber being from about 3 parts of rubber by Weight to 1 part of ber, said ber being about 1' mm. to 2 mm. in length and being uniformly-disintegrated and dispersed through said composition by mastication, said composition being capable of retaining during vulcanization sharp embossing marks imparted'to the unvulcanizedcoating, and a thin halogenated layer of shellac thereon, said coating being exible and free from rubbery feel.

4. An-articial leather comprising a backing of fabric napped on one side and having secured to the opposite side thereof a layer of vulcanized rubber cement and an indurated layer of vulcanized rubber composition containing at least 67% of rubber and the remainder wood ber and nonearthy material, thel ratio of wood ber to rubber being from about 2 to about 5 parts of rubber by weight to 1 part of ber, said ber being about 1 mm. to 2 mm. in length and being uniformly disintegrated and dispersed through said composition by mastication, said composition being capable of retaining during vulcanizetionsbarp embossing marks imparted to the unvulcanized coating, and a thin halogenated layer of shellac thereon, saidcoating being exible and free from rubbery feel.

5. An articial leather comprising a backing of fabric napped on one side and having secured to the opposite side thereof a layer of vulcanized rubber cement and an indurated layer of vulcanized rubber composition containing at least and not more than about 75% of rubber and the remainder wood ber, curing ingredients including sulphur and coloring material, theratio ot wood ber to rubber being from about 2 to about 5 parts of rubber by weight to 1 part of ber the amount of rubber present being about 100 times the amount of sulphur present, said ber being about 1 mm.. to 2 mm. in length and being uniformly disintegrated and dispersed through said composition by mastication, said composition being capable of retaining during vulcanization sharp embossing marks imparted .to the unvulcanized coating, and a thin halogenated layer of shellac thereon, said coating being exible and free from rubbery feel.

6. An artificial leather comprising a backing of fabric napped on one side and having secured to the opposite side thereof a layer of vulcanized rubber cement, a layer of vulcanized rubber com-1 position containing at least 50% and not more than about rubber, and the remainder bers of newsprint paper and non-earthy material, the ratio of newsprint paper to rubber being from about 2 to about 5 parts of rubber by weight to l. of newsprint paper, said newsprint paper being thoroughly and uniformly disintegrated and dispersed through said coating composition by mas# tication until the vulcanized coating will retain sharply and distinctly embossing marks which are imparted to the unvulcanized coating before vulcanization, said coating being exible and freevfrom rubbery feel.

7. A coating composition suitable for coating exible base material for the manufacture of leather substitute which comprises at least 50% to about 75% rubber, and the remainder wood ber inthe form'of newsprint paper, curing ingredients and coloring material to impart color and the desired vulcanizing properties to the rubber, said ber being present inthe ratio of about 1 part of ber to about 2 to about 5 parts of rubber and being uniformly disintegrated and dispersed through the composition by mastication, the composition being capable of retaining during vulcanization sharp embossing marl-rsV Davm J. sUILIvAN. 

